The disclosure relates generally to seating cushions for the prevention of pressure sores and, more particularly, to a sensor for connection to an inflated air cell cushion that detects immersion of a user into the air cell cushion.
Air cell cushions are known to the art. Generally air cell seat cushions are used by individuals who must remain seated for extended periods of time, for example, a disabled individual who uses a wheelchair for locomotion. Larger air cell cushions, generally configured as mattresses, are used by non-ambulatory or bed ridden individuals. In any event, inflatable air cell cushions are employed to prevent pressure sores on the buttocks or at other bony prominences. These air cell cushions provide support, while distributing weight, generally uniformly through a multiplicity of interconnected air cells.
The typical air cell cushion includes a base and an array of interconnected, upstanding individual air cells, usually arranged in transverse and longitudinal rows. An air inflation tube is in fluid communication with one of the cells. The inflation tube includes a screw type valve. The air cell cushion generally has a stretchy cover. A representative embodiment of such an air cell is disclosed in U.S. Pat. No. 4,541,136, which is incorporated herein by reference.
For proper seating on the cushion, the cushion is placed on a relatively firm or hard support surface, such as a wheel chair seat or other type of seat or chair. The individual or caregiver (either one referred to as “the user”) opens the valve and pumps air into the cushion until it is well inflated. The user then sits on the cushion and air is released through the valve until the user is optimally immersed in the air cell cushion. The valve then is closed. Proper immersion optimizes weight distribution and reduces pressure on the anatomy.
Heretofore proper immersion has been determined by a hand check method. That is, the individual or caregiver inserts a hand between the body and cushion to determine when the user is properly immersed in the cushion. Although this method has worked adequately, it is a subjective measurement. Moreover, the depth of immersion can vary depending upon who is checking immersion depth.
It would be advantageous, therefore, to have an apparatus that can objectively detect optimal immersion depth. Such an apparatus should reliably and consistently detect optimal immersion depth for a variety of users regardless of the volume of the cushion, user size or weight.